class TTY::Prompt::Paginator
Constants
- DEFAULT_PAGE_SIZE
Public Class Methods
new(options = {})
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Create a Paginator
@api private
# File lib/tty/prompt/paginator.rb, line 11 def initialize(options = {}) @last_index = Array(options[:default]).flatten.first || 0 @per_page = options[:per_page] @lower_index = Array(options[:default]).flatten.first end
Public Instance Methods
max_index()
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Maximum index for current pagination
@return [Integer]
@api public
# File lib/tty/prompt/paginator.rb, line 22 def max_index raise ArgumentError, 'no max index' unless @per_page @lower_index + @per_page - 1 end
paginate(list, active, per_page = nil, &block)
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Paginate collection given an active index
@param [Array] list
a collection of choice items
@param [Integer] active
current choice active index
@param [Integer] per_page
number of choice items per page
@return [Enumerable]
@api public
# File lib/tty/prompt/paginator.rb, line 39 def paginate(list, active, per_page = nil, &block) current_index = active - 1 default_size = (list.size <= DEFAULT_PAGE_SIZE ? list.size : DEFAULT_PAGE_SIZE) @per_page = @per_page || per_page || default_size @lower_index ||= current_index @upper_index ||= max_index # Don't paginate short lists if list.size <= @per_page @lower_index = 0 @upper_index = list.size - 1 if block return list.each_with_index(&block) else return list.each_with_index.to_enum end end if current_index > @last_index # going up if current_index > @upper_index && current_index < list.size - 1 @lower_index += 1 end elsif current_index < @last_index # going down if current_index < @lower_index && current_index > 0 @lower_index -= 1 end end # Cycle list if current_index.zero? @lower_index = 0 elsif current_index == list.size - 1 @lower_index = list.size - 1 - (@per_page - 1) end @upper_index = @lower_index + (@per_page - 1) @last_index = current_index sliced_list = list[@lower_index..@upper_index] indices = (@lower_index..@upper_index) return sliced_list.zip(indices).to_enum unless block_given? sliced_list.each_with_index do |item, index| block[item, @lower_index + index] end end